Mold for casting printers&#39; rules, leads, and the like



June 17, 1952 J. c. MOCAULEY MOLD FOR CASTING PRINTERS RULES, LEADS, ANDTHE LIKE Filed Jan. 31, 1950 INVENTOR.

ATTORWL-V Patented June 17, 1952 MOLD FOR CASTING PRINTERS RULES, LEADS,AND THE LIKE John C. McCauley, Mattapan, Mass., assignor to LudlowTypograph Company, Chicago, 111., a corporation of Illinois 7 7Application January 31, 1950, Serial No..141,376

2 Claims. 1

The present invention relates to improvements in the production of metalstrips in the form known in the printing art as rules, leads and thelike, such strips being formed directly from a body of molten metal bythe casting of a continuous strip through a mold. The casting preferablyis supplemented by a feeding device which forces metal into the mold anda, device which applies a pull to the finished strip as it emerges fromthe mold.

Molten metal is forced into the base end of a channel in the mold,within which the metal is cooled and set, and is moved gradually outthrough the outer open end of the channel as an integral part of thefinished strip. In order to ensure rapid cooling and setting of themetal, and thereby to increase the permissible rate of feed, the mold iscooled, usually by means of a Water jacket extending around the mold.

The molds employed in the manufacture of printers leads and rules, inaccordance with the continuous or intermittent casting process abovereferred to, are required to be strongly and accurately constructed towithstand the extreme fluctuations of heat and cooling, and at the sametime to produce a metal strip which will meet rigid specifications ofmeasurement and uniformity.

The present invention is an improvement upon a mold of the general typewhich comprises a pair of plates separated by two liners or spacerswhich form the sides of the mold, these parts being rigidly securedtogether by machine screws. Because the assembly and accurate adjustmentof these molds requires factory supervision and facilities, it has beenfound desirable to provide separate molds for each different shape andthickness of lead or rule.

Objects of the present invention are to provide a, novel and improvedmold for use in the manufacture of printers leads, rules, and the likestrip material, which is more strongly and efficiently constructed thanthe molds previously available in the art, which is further constructedand arranged to permit of a more rapid rate of cooling and of settingthe molten metal, and a substantially faster rate of extrusion of thefinished strip from the mold, and which is well adapted to be takenapart and reassembled in the field and adjusted for the production ofrules and leads of difierent dimension, without loss of accuracy oreffectiveness in use.

With these'and other objects in view as hereinafter may appear, theseveral features of the invention consist of the devices, combinations,

2 and arrangement of parts hereinafter described and claimed which,together with the advantages to be obtained thereby, will be readilyunderstood by one skilled in the art from the following descriptiontaken in connection with the accompanying drawings, in which Fig. 1 is aside view of a mold illustrating in a preferred form the severalfeatures of the invention;

Fig. 2 is a sectional view taken on a line 2- 2 of Fig. 1;

Fig. 3 is an exploded view of the mold comprising the mating moldmembers, and a pair of shims;

Fig. 4 is a sectional view taken on .a line 3-4 of Fig. 2 to illustrateparticularly the arrangement of the cooling conduits in the male moldmember; and

Fig. 5 is a sectional view of the mold taken on a line 5-5 of Fig. 4.

The mold illustrated in the drawing as embodying in a preferred form theseveral features of the invention comprises a pair of plates l9 and 12which are constructed and arranged to provide the mating elements of anadjustable mold. The plate H] has mounted on the inner face thereof ablock H which forms the male element of the mold. The block I4 issecured to the plate H] by means of aseries of four machine screws E5.The plate l2 has mounted along the edges of the inner face thereof twobars 16 and I3 which provide the side wall members of the castingchannel of the mold. The bar I8 is l.- shaped, being provided at one endwith a transverse extension 20 which may be formed integrally with thebar [8, or as .a separate piece and which extends across the face of themold member I2 into engagement with the barv l5, and forms an end wall,or closure, for the base end of the casting channel. The bars (6 andlorespectively are rigidly secured to the plate 12 by means of a seriesof machine screws 24, the heads of which are recessed into the surfaceof the bars I 6 and 18 respectively. A conduit 26 cut through thetransverse extension '20 of the bar IQ of the mold provides an entranceor gateway through which molten metal is forced into the casting channelof the mold. It will be understood that while the mold in the preferredform is constructed to include an end wall having a conduit outtherethrough, the invention in "the broader aspects is not limited tothe specific construction shown. Theend wall 20 may, for example, beomitted and the supply nozzle connected directly across an open base endof the casting channel.

For adjustment of the thickness or point rating of the strip materialcast in the mold, two shims or spacers 28 and 3B are provided betweenopposed faces of the side wall bars I6 and I8 respectively, and therecessed edges formed by the inner face of the plate In at each side ofthe block I4. The parts of the mold, including the plates I2 and I4, andspacers 28 and 36, are held rigidly together by means of a. series ofmachine screws 32 arranged with the head portions thereof recessed intoplate In and with their opposite ends threaded into plate I2. Adjustmentof the thickness or point rating of the finished strip is determined bythe choice of spacer members 28 and 30 which in turn de termine theposition of the inner face of the block I4 with relation to the opposedinner face of the plate l2.

To avoid sticking or the cast metal to the mold and to assist generallythe process of extruding the cast strip from the mold, thecross-sectional area of the metal receiving and casting channel isincreased in each dimension by approximately two thousandths of an inch(.002) along the length of the channel, from the base, or receiving end,to the outer end from which the finished strip is projected. Thisincrease in the vertical cross-sectional dimension is obtained bydiverging the opposed walls of bars I6 and I8. Variation of the shortertransverse cross-sectional dimension is obtained by the shaping of theinner face of the block I4 so that it diverges with respect to theopposed face of the plate l2. The top and bottom edge of the block 14are similarly formed in a diverging relation to one another in order toensure a snug fit between the edges of the block I4 and adjacent wallsof the bars l3 and I8. It will be understood that the desired dive ge ceof the faces of block 14 and plate I2 may be obtained in any alternativemanner as for example by the use of tapered spacer members.

To insure that the corners of the cast metal strip may be accuratelyformed, and in order to prevent leakage of the molten metal, a veryclose fit with a minimum tolerance is required between the sides of themale mold member I4, and side bars I6 and IB forming the side walls ofthe mold. The slight taper of the member 14 above noted, is ofconsiderable value in assembling the parts of the mold since thenarrowed portion of the block I4 can be fitted between the relativelymore separated outer ends of the side walls of the channel provided bythe bars and I8 and thereafter moved lengthwise into position.

In carrying out the present invention, a water cooling system isprovided which takes the form of passages in the block [4 and in theplate I2, which supply water or other coolant directly to the faceportions of the mold in contact with the molten metal. The plate I4 isformed with two longitudinally extending drilled conduits 34, 39, and avertically connecting drilled conduit 3? which may be formed preferablywith a number 38 drill. The ends of the conduits are then sealed off orplugged.

Supply and exist connections for the coolant are provided at the openend of the mold. These connections take the form of a transverse bar 39and gasket 40, secured to the exterior surface of the mold plate In atits outer end.

Transverse drills extending inwardly through the transverse bar 39 andmold plate I0, and into the block I4 are arranged to intersect with thelongitudinal conduits 34, 36. To avoid any possibility of leakage, acoolant supply tube 46, and a coolant return tube 48 are fitted intosaid transverse drills and intersect with the longitudinal passages 34,36. In order to insure an open connection between the supply tube 46 andpassage 34, and similarly between return tube 48 and passage 36,passages 34, 36 are preferably drilled after the tubes 46, 48 are inplace thus causing the drill to cut away obstructing portions of thetubes.

Coolant is supplied in a similar manner to cool the inner surface ofmold plate I2 through longitudinal passages 50, 52, a vertical passage54 (see Fig. 5), a coolant supply tube 56 and a coolant return tube 58.A vertically disposed supporting plate 60 and a gasket 62 are secured tothe outer surface of the mold plate I2 at its outer end by means ofmachine screws 64 and 66. The coolant supply and the coolant returntubes 56, 58 are inserted into transverse drills passing through thesupporting plate 66 and mold plate l2 to intersect the longitudinalpassages 50, 52. It will be understood that applicant is not limited tothe specific construction of the coolant supply conduits shown, andthat, if so desired, the transverse bars and gaskets could be omittedin'favor of a direct connection of the supply conduits to the male andfemale mold members respectively.

The improved mold assembly above described has a number of veryimportant advantages over extrusion molds provided by the prior art. Theconstruction and arrangement of the mold members is such that thecoolant is more efficiently shielded from the casting channel of themold, and those surfaces of the mold members engaging the shims orspacers 28, 30 which are employed to control the thickness or pointrating of the cast strip, are free from contact with either the moltenmetal or with the coolant along the length of the casting channel. Aswill be readily evident from an inspection of the drawing, the moltenmetal is entirely contained by the mating elements of the mold within acasting channel which comprises the plate I2, the side wall members [6,

l8, and end wall 20, and the block I4 which is closely fitted thereto.

The arrangement above described of the coolant supply and return tubeswhich serve as linings for the supply and return conduits, and whichbridge certain contacting surfaces of the parts from which the moldmembers .are constructed, has been found to entirely eliminate leakageof coolant, which might otherwise result from any separation of thesecontacting surfaces caused by heat induced expansion or contraction ofmold members when in use,

A highly rigid and efiicient construction of the mold assembly isprovided by the arrangement of the adjustable mold members andassociated spacer members in which the shims or spacers 28, 3B, are wellremoved from the casting channel and need not be fitted together withthe care required for previous constructions to maintain smooth surfacesand tight joints in the casting channel, and in which the moldplateswith the side walls and spacer members there between are rigidlysecured together by screws passing through the side walls and spacermembers of the mold.

The arrangement of the male and female mold members in which the sidewalls I6, I8 of the female member and the sides of the block I4 engagingtherewith diverge slightly toward the open end of the casting channel isof substantial importance in the illustrated construction in that itpermits the mold to be taken apart and readily assembled into a tightfitting unit by even an unskilled workman who in assembling the moldwill insert the block [4 between the side walls IS, IS toward the openend of the casting channel and thereafter slide it lengthwise intoposition toward the base end of the mold.

It will be understood that the invention is not limited to the specificembodiment shown, and that various deviations may be made therefromwithout departing from the spirit and scope of the appended claims.

What is claimed is:

1. A mold for use in the casting of continuous printers leads, rules-andthe like strip material which comprises a female mold member providing afiat casting channel having an open discharge end, and a base inlet endfor molten metal with side walls of a height greater than the greatestthickness of lead to be cast in the mold, a male mold member comprisinga block arranged to extend between and closely fitted to said side wallsand having recessed outwardly extending edge portions overlying saidside walls, spacers of predetermined thickness interposed between saidside walls and said recessed overlying edge portions of the male moldmember, and fastenings passing through the edge portions of said moldmembers including said spacers and walls for fastening together the maleand female mold members.

2. A mold for use in the casting of continuous printers leads, rules andthe like strip material which comprises a female mold member providing afiat casting channel having an open discharge end and a base inlet endfor molten metal with the opposite walls thereof diverging slightly fromthe base inlet end to the open discharge end including divergent sidewalls of a height greater than the greatest thickness of lead to be JOHNC. MCCAULEY.

REFERENCE S CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 257,307 Fitzsimons May 2, 18821,476,967 Hedly Dec. 11, 1923 1,503,479 Coats Aug. 5, 1924 1,567,431Elrod Dec. 29, 1925 1,671,088 Dahl May 22, 1928 1,804,275 Redmann May 5,1931 1,862,982 Redmann June 14, 1932 1,946,488 Dahl Feb. 13, 19342,251,858 Snell Aug. 5, 1941

